Beauty isn't the only cool thing that comes from age.

Waiting a few years to start your family may give you some unexpected benefits: Women who are able to give birth after age 33 tend to live longer than those who stopped having children before age 30, according to a study from the Boston University School of Medicine.

"Of course this does not mean women should wait to have children at older ages in order to improve their own chances of living longer," says study co-author Thomas Perls, M.D., professor of medicine at Boston University School of Medicine. "The age at last childbirth can be a rate of aging indicator. The natural ability to have a child at an older age likely indicates that a woman's reproductive system is aging slowly, and therefore so is the rest of her body."

The study, published in the journal Menopause, did not prove causation, but it did find that women who gave birth after age 33 had twice the odds of living to 95 years or older than those who had their last child by age 29.

Researchers said the link exists because gene variations that enable women to have babies by natural means at a later age may also be tied to living longer lives. "If a woman has those variants, she is able to reproduce and bear children for a longer period of time, increasing her chances of passing down those genes to the next generation," says Perls.

Previous research has turned up similar results to this one. An earlier study from the New England Centenarian Study found that women who had children after age 40 were four times more likely to live to be 100 years old than women who had their last child at a younger age.

More research is still needed, says Perls. The information found in this study shows the importance of research about genetic influences and reproductive fitness, because these trends can affect susceptibility to age-related disease.